Update README.md

Version 6.0

Version 6.0 beta

Tag syncing, diff improvements and plenty of tweaks and fixes

FTP manager, new settings available and lots of minor bug fixes & tweaks

Improved and fixed saved issues, auto-logout setting added plus sessi…

…on keep-alive added also, match brackets added, security fixes and many other small updates and tweaks

New save system, LZ compression, improved code folding, faster load a…

…nd save, fixed jamming and many errors, new drag icons, XSS tweaks, new themes and more!

v5.3

Version control system, most FTP features set up plus lots of minor fixes and improvements

FTP connectivity, simultaneous tag editing, editor height tweaks, err…

…or highlighting, tabbed settings section, preview window tweaks, plus lots of enhancements and bug fixes

Find/replace cycling now with CTRL+F/G for next/previous, 5x zoom hel…

…per on image eyedropper, can open remote files and go to line now, better bug handling with friendly messages and console.log error info, ino files for Arduino plus plenty of bug fixes and other enhancements